I have set the heater at 24-25C which should be the safe fallback temperature in case the temperature inside the aquarium drops. If you have an open aquarium with the light tubes on top of the tank you might wonder what I am talking about. You see – the Juwel tank is closed tank which means that the light tubes are inside the tank right next to the water.

The light tubes also emit heat and since the tubes are right next to the water it has a significant effect on the heating of the eco system. Despite that I have set the temperature to be 24-25C in the heater, I constantly measure water temperatures of 27-28C. I haven’t found an easy way to cool down the tank since our apartment temperature is anyway quite high too, even if not 27C. I have and air diffuser plugged in to the Juwel Bioflow pump which creates extra air flow to the water. This is recommended in any case, but necessary with high temperatures.

Do you think my water temperature is too high for normal fish like guppies or platys?

I have also been wondering if the temperature has a negative effect to any plants? I guess not since they look pretty healthy, but somehow this temperature makes me nervous. I hope in vain?